Traditionally, antibacterial agents and antiseptic agents have been used in various fields such as food products, cosmetic products, oral products, pharmaceuticals, medicated cosmetics and daily goods to prevent deterioration in quality or flavor associated with the growth of harmful microorganisms or to deal with unpleasant odors associated with the growth of microorganisms.
For example, food products are added with antiseptic agents for longer shelf life and food poisoning prevention. Oral products are added with antibacterial agents to prevent and control the growth of cariogenic bacteria and periodontal bacteria that cause tooth cavities and periodontal disease, respectively. Moreover, cosmetic products are added with antibacterial agents to control the growth of armpit odor bacteria, dandruff-causative bacteria and acne bacteria that cause armpit odor, dandruff and acnes, respectively.
However, since conventionally used antibacterial agents and antiseptic agents do not have adequate antibacterial activity or adequately wide antibacterial spectrum, little of them show satisfactory effects. In addition, even agents having antibacterial activities and wide antibacterial spectra are not always satisfactory in terms of safety that they could be great pressure on human and the environment.
For example, paraben conventionally and frequently used as an antiseptic agent in cosmetic products has a narrow antibacterial spectrum and a weak activity and thus has not always been a satisfactory antibacterial agent. Triclosan known as an antibacterial substance with a stronger antibacterial activity and a wider antibacterial spectrum harbors a chlorine atom in its molecule and thus limited of its use in products for the concern about the effects on the environment and human body.
In beverage industry, heat sterilization is employed to prevent reduction of commercial value associated with proliferation of bacteria. The heat sterilization, however, has a problem of greatly deteriorating the flavor of the product. Thus, in addition to minimal heat treatment, addition of a substance having an antibacterial effect such as sucrose fatty acid ester is proposed to deal with proliferation of bacteria. The ester, however, is poorly dispersed in an acidic region and likely to crystallize, causing turbidity and sediment in an acidic beverage and thus pointed out of its disadvantage of reducing the commercial value of the product.
Moreover, due to the recent increase of sanitary and safety concerns by the consumers, highly safe antibacterial agents with higher antibacterial actions and wider antibacterial spectra have been desired especially for products that directly touches human body such as food products, oral products and cosmetic products.